Thomas Crowe, an attorney for Officer Samuel Ocasio, said federal prosecutors won't be able to prove that Ocasio took money to refer vehicles, and said that the towing company owners, who are expected to testify Tuesday, are making false allegations.

"There's nothing that says an officer can't suggest to someone that a particular place is a good repair shop," Crowe told jurors.

But prosecutors say Ocasio and Kelvin Manrich, whose attorney deferred his opening statement, "succumbed to greed" and said the evidence includes wiretapped phone conversations, video surveillance and text messages, as well as testimony from key members of the conspiracy.

"Nobody wins when two Baltimore police officers are on trial, but at the end, the proof will be overwhelming," Assistant U.S. Attorney Tonya Kelly told the jury.